What about fiber wads and smokeless?
I have read that if you go this route to use
waxed fiber wads to lessen lead fouling.
While I have little experience with that combination I did load and shoot several hundred rounds using plastic wads with the shot cup removed - I had a tightly choked double that I was trying to open the pattern on. I got tremendous lead fouling. Using Ed's Red, a drill motor, and a brass brush it would take an hour and a half to get the lead out. Some pieces would come out as big as a 1/2" across and also a fine lead/Eds Red slurry.
I am experimenting with Alcan ring-waxed wads Stallones kindly gave me. I am currently using them in brass shells loaded with smokeless Rex III in 16 gauge. I have not reached any conclusions about waxed fiber wads yet.
Best,
Mike