Why not pop a call into Mojo or Loco to see if you can buy just foam rings?
Yes you can clean them up reasonably, but why bother when the work load installing new foams is the same plus you can and freshly soak in 50:50 float/10wt over night? and know you’re doing better.
Still important to do seals also! Maybe every other foam swap you do seals.. or if teh foams you remove are mucky.. thats a sign the seals are not working effectively.
Although, i just did 2 x 32mm kashimad forks yesterday.. the skf seals are pretty effective.. not a jot of muck in the oil of my Float 120’s thats been run for an entire summer and spring.