It just accumulates as a congealed mess in between your patients toes. :)
For some things it's great.
Really painful, deep HD's can be enucleated far deeper than with a blade.
Some people cannot stand to have nails reduced with nippers - Podospray is a more comfortable option than a regular drill.
One of the most useful things I've done with it is to remove the nail spicules you sometime get post NS. I use the fine burr to get right in the PNF/sulcus to reduce all the nail material and callus - untill it bleeds a bit. This then allows the phenol a far better chance of killing off the small patch of persistent matrix. I've done that a couple of times now and it's worked. That's on folk that have had a revision procedure and still had spicule regrowth.
It's also very effective at completely clearing heavy OP/callus in slucus.
Basically, it does everything a nail drill does with the advantage of also being able to reduce callus.
Well obviously you breathe some of it in. And it gets in your eyes, nose and ears a bit too.
Obviously you need to wear appropriate PPE.
I only use it maybe twice a month and would suggest it is less hazardous than dry filing of nails with a diamond deb, where you can see the dust particles floating around in front of you. We don't routinely wear a mask for that either.
I tend to find that the podospray can be quite time consuming especialy if you have 3/4 big fibrous corns to get rid of! but you can get an awfull lot more out that you would be able to with a blade!