Or you could soak it in prescription strength urea for a couple of days to get the nail to fall off. Less collateral damage that way.

OP might be talking about a procedure where a podiatrist or dermatologist kills the mis-growing edges of the nail root. The remaining root grows a narrower nail, but hopefully a straighter one. Sometimes the process doesn’t work the first time (hard to judge how much cell-kill stuff will get just the edges and not damage the middle) and has to be repeated.