For stubborn polish, go straight to acetone. Regular remover doesn’t work.
For everyday colors that come off easy I stick with the gentler stuff, because otherwise my nails feel like sandpaper after.
For glitter, one of those little sponge pots works great.
Your boyfriend’s right. Same stuff. The hardware store version is identical to what you’d get at a beauty supply. They add denatonium benzoate to make it taste bitter so nobody tries drinking it.
Higher acetone is the only way to go for sparkly or red polishes. Letting soaked cotton sit on the nail for a minute makes a big difference. For something sheer like a basic pink, regular non-acetone works fine.