I have a 1957, to-35 and it has a oil bath air filter.
I cleaned the air filter in this manner:
I took the air filter off the tractor,
secured a 5 gal plastic bucket, placed filter in the bucket and filled bucket with kerosene until the filter mesh was covered.
let the filter stand in the kerosene over night,
with fresh kerosene, I washed the filter in and out of the kerosene,
do this over and over, changing the kerosene bath until after multi dips of the filter in the fresh kerosene, the kerosene remains clean.
then let the filter air dry, drip dry for another 24 hrs.
placed it back on the tractor, tractor never missed a beat, should have cleaned the filter many years ago.
this is how I did it, not the only way, but it worked.
above all things, do not, do not try to take that wire mesh out of the filter, have heard it is very difficult, to impossible to get it back into the filter housing.
good luck and let us know how I works out for you.
safety note: use kerosene, not gasoline, if you do not get all the cleaner out of the filter, you do not want to suck gas fumes into the intake.
I use 30 weight oil in the oil bath cup