Originally Posted by
coleossus
Absolutely not sneakers - will leak too much energy. I'd do it barefoot - lifted into the 350s barefoot before I bought lifting shoes. If you want to do it the cheap way, do it barefoot with a plate under your feet. I wouldn't use dress shoes more because of personal preference than anything and I have experience squatting barefoot.
I do beltless squats at a 10% reduction, personally. 15-20% is safe. If you're de-loading by 25% already, though, I don't know why you'd need to deload another 10-15% unless you were very carefully managing recovery/work stress.