Little known fact, babushka also means butterfly in Russian (if you put the stress on a different syllable). So if you do not like the old lady as a marketing image you can always go with a pretty butterfly.
There's no "technically" about it. That's just what the word means. It's irrelevant how similar they sound to the English ear; you might as well argue that "the" is interchangeable with "duh".
Also, contrary to the GP, there's no difference in stress, which is on the first syllable in both words. The reason they're different words is that "sh" vs. "ch" is a phonemic distinction in Russian, just as it is in English. That's why we distinguish between "sheep" and "cheep", for example, and would regard it as bizarre to conflate them.
