My wife likes lattes. I don't have an espresso machine but there are other ways to make coffee-concentrate, such as my Aerobie Aeropress and my Moka Pot. There are several ways to heat and foam milk but, anecdotally, the best way is to use steam.
The Stovetop Steamer is not very popular, even in coffee newsgroups, and the brand that appears most often is made by Bellman. I had read a number of reviews of the Bellman and none of them seemed to answer my questions (which included ...where to buy one in Toronto, Canada). I finally found the Canadian distributor in Montreal and ordered it on-line. When it arrived I started to dig out answers to my questions.
The Steamer is a pot (well ...a pressure vessel). There is a Bakelite handle, essential because in operation it is quite hot and needs to be moved around. Between the handle and the vessel there is an overpressure valve which relieves steam when necessary. Opposite the handle is the wand assembly which includes a needle-valve to control the flow of steam. At the top there is a big black knob. When you unscrew and set it aside you can remove a bonnet and an insert. The knob, bonnet and insert are all fitted with gaskets so they seal tight against the steam pressure. I puzzled some about the purpose of the 'insert'. I think it is to shield the steam outlet from boiling water so that liquid water does not sputter out of the wand. The entire assembly is well thought out, good looking and has nice fit and finish.
When filled to just below the handle (as recommended) the Steamer holds around 30 fl oz. After some use I found it unnecessary to fill it that full. I fill it half an inch above the midline, probably 20 fl oz.
In some newsgroup postings I read that "...you need a gas-stove". In my kitchen I have a glass-top electric, coolest of all stoves. With a small burner on 'high' I was able to raise full steam including popping the relief-valve. However, with that coolest of stoves, initial heating with 30 oz took 12 minutes (too long). Filling it from my hot-tap reduced the initial heat-up time to 3:30 minutes.
But how much water do you really need? With water filled to half an inch above the midline, I practiced foaming up four 8 oz batches of soapsuds and then an 8 oz batch of milk. When I opened it up after cool-down, the level had dropped to half an inch below the midline. I had a sense that I could have done a good deal more frothing without needing a water refill.
Be aware that the Steamer will 'steam' minutes after you remove it from the heat source and that it takes a long time to cool down to the point that you can open it up. This heat retention adds flexibility in its use.
In case you were wondering, the steam wand nozzle only has one hole. And with that one hole, there is much visible swirl and agitation when you open the valve fully. And, while on the burner, there is ample steam to support that agitation.
On the internet there are hundreds of articles on the best way to make micro-foam using steam. You should (or should not) start at the surface to draw air into the milk. You should (or should not) chill the pitcher in your refrigerator. You should (or should not) find the right angle for the steam wand. In my local coffee shop, the barista makes great micro-foam as follows: She slops milk into the pitcher, pushes the wand down into the pitcher, turns on the steam, goes away to take muffins out of the oven, returns a minute later, turns off the steam, wipes the wand and pours the foamed milk into my latte.
So, with my Espro Toroid 12 oz pitcher I cracked the valve to get a bit of steam, plunged the wand in half an inch from the bottom, cranked open the valve and watched as the foam built up. There was lots of agitation. Because the pitcher has a bell-bottom I could watch the progress as the foam increased and climbed up the narrowing sides. I was not sure if (or how) I was drawing in air but the foam definitely increased and it was fine textured with no big bubbles on top.
My recipe for Hot Chocolate: Dissolve 4 heaping tsps of Carnation (brand) hot chocolate powder in 3 fl oz of hot water in a 9 oz mug. Foam up 4 fl oz (1/2 cup) of 2% milk. Pour foam into hot chocolate, gently stir and serve. You'll make friends.
In conclusion, the Bellman Stovetop Steamer works well. If I had to find fault it would be that the needle valve does not shut off tight. At full pressure there seems to be a tiny whisper of steam coming out of the wand. OTOH, it could also be a design feature, to heat and not to allow milk to intrude into the wand, where cleaning would be a problem. Everything works well. And it is smaller and less expensive than an espresso machine, as a source of steam for milk frothing. And, it can find storage in a cupboard and not take up counter space.