Be careful with the isopropyl on some plastics. Victorinox's 'cellidor' plastic handles on their Swiss Army Knives will soften and/or distort in shape (warping, shrinking) if isopropyl alcohol is used to clean them. I found that out the hard way. One of mine softened enough that I left an embossed image of my thumb print on it, after cleaning it with IPA. Good news is, I used IPA again to 'erase' it. But the handle scales still ended up a little warped after they dried; that also affects their ability to hold snugly onto the toothpick & tweezers, inserted underneath the handles. The toothpick in mine kept falling out on it's own, after that misadventure.
Some dyed bone handle scales might also shed some color if solvents like IPA are used to clean them. Most of the time, it's not a big deal, as any dye coming off is usually excess that's left from the factory, and hasn't really been absorbed fully into the bone. But some handles might noticeably fade with even a little bit of dye loss.
IPA will also dry out natural materials like wood or stag. So, if you use it, you might also follow up with something to recondition the handles so they don't get too dry and crack or split. But generally, I'd avoid using IPA on those in the first place.
IPA is fine for cleaning blades and flushing moisture out of blade wells and pivots, on knives that otherwise won't be harmed by it. Just be aware of which materials can tolerate it, and which ones can't.
