[J P Stein]

I suppose one can clean out the crud without removing the rocker pannel, but......

The whole area needs a close look.
The jack pad support (the piramid shaped shaped thingy) creates a void. There is a drain(?) hole in it.....or it could be a fill hole.....never did figure that out. There is NO preservative of any kind in there.....nada. There is rust in there, guaranteed.
I opened them up and found out. Decided "I don't use these suckers, nohow ...be off with you". The old carbide rotary bit & die grinder gig. It's an ugly job.
This may be bit extreme for most folks, but one less thing to worry about.

A guy could fill em' with a rust killer or sumthin' and then let it drain out.