When first starting up, my Handy sometimes makes grinding noises that sound like a duck. It stops within a few minutes but it’s been happening for several months. I don’t want to risk voiding the warranty so I haven’t done anything about it.
If I ever decide to lube it, I’d try to open it to directly apply oil to the proper areas. I wouldn’t just spray into the device. I would also likely use Mineral Oil for Hair Clippers. I used this once to repair a DVD player and extended it’s life by about 4 years.