Hello John Keim and all
On the plastic foundation,  I use pierco and when it needs renewed(from
moth damage or a deadout) I scrape it down and wait for a cool day. Then
I use my air compressor to blow off the cocoon stubs. I remember reading
that someone else used a high pressure washer.  The air compressor is
less messy I would think.

On applying fresh wax to the foundation try a paint brush and thin the
bristles off one side of the brush, but the bees build the comb back up
without problem when I use the air compressor to clean off the foundation
as it doesnt remove the entire coating just the bottoms of the comb
contents.
hope this helps
hope you already have a compressor, a powerwasher may be cheaper?
Al Boehm