Opinions on thrifted undershirts being used for fashion DIYs?

Today I went thrifting for the first time ever with some of my friends and I made a bit of a misjudgement. I saw this really cute lacy tank top and decided to get it, only to realise it was an undershirt instead.
I don’t feel comfy wearing something that was on those especially sweaty areas on someone’s bare skin, but I’m wondering if anyone here has experience with washing these kinda more delicate less high quality materials and using them for diys.
More specifically I’d probably use it to make heart shaped patches on some other clothes or use the lace to make some kind of design, so it wouldn’t be touching my bare skin for while wearing. If it isn’t really clear what I’m getting at I mean it from a hygenical standpoint. I’m new to all of this so any advice even if it’s not something I specifically asked for in this thread is appreciated.