In Russian, pronunciation of Е depends on its placement. If preceded by a consonant, it's pronounced like a "softer" Э. A bit like "bet" vs "bat" in US English. It's only pronounced as "ye" if it's the first letter of the word, or preceded by a vowel, soft sign (Ь) or hard sign (Ъ).
In Ukrainian, Є is similar to Russian Е, but it's not modified if preceded by a consonant - in these cases it's typically replaced by i. Ukrainian Е is indeed about the same as Russian Э. And Russian Ё is replaced by combinations ЙО or ЬО.
Meanwhile, most sex shops: selling jelly which just straight up melts with time, TPE/TPR which are porous and might melt when boiled and therefore pretty much impossible to keep clean, PVC which they promise doesn't contain phthalates this time, and silicone that has about a 50% chance of actually being platinum cured. DIYers can't be much worse, as far as I know, they either outright state what methods and materials they use or will provide them upon request.