I clean before hunting season regardless of use. I had a gun become a paperweight from carbon flakes falling out of the suppressor into the action while packing in (gun attached to my pack with barrel up).
I use TBAC suppressors so cleaning is simple. Plug small hole, fill with CLR, set it aside for a few hours, repeat.
Pro tip…CLR will "bubble" on a dirty suppressor, so fill it 3/4 full, let it settle down, then fill up. You don't want CLR overflowing onto the nitriding on the outside, it'll eat it.