Roserade was a pretty big help for me. Grass moves get boosted, and nature power turns into STAB energy ball. I did have to switch out against Swellow, but an electric or rock type should be able to handle that just fine. (I kinda got lucky since my shiny stone was found through mining tho)
Of your current party, Arcanine seems like the most useful since it can change the field with flame burst or heat wave. Once you do that grounded pokemon will take type scaled damage from the fire so i would recommend waiting until your steel types get KOd (Bewear takes double damge from fluffy too)
Alternatively, something like nidoking that learns sludge wave can turn the field into the corrosive field to stop the healing effects and prevent clefable from using its seed. I think this works better for your current team since your steel types will be immune to the entry damage. If one of your mons knows a steel type move i would make sure it has enough hp to take on clefable