channels between panels?

[MaxT]

Hello,
A couple newbie questions!

What do you guys do about the "channels" between panels? (on my car they are just under a quarter of an inch wide)

1) When correcting with a DA polisher, do you tape over them so the product doesn't get in? What if the product got in, what do you use to get it out before it dries (towels don't really fit deep enough)?
2) What if there is visible damage that you need to polish out, in my case from water with rust that leaked into those channels (i polished the panels with wolfgang TSR and a hand applicator and it came out great, but can't get into the channels)?

Would appreciate some advice!

PS: I'll try and take some pictures later tonight.

[Becciasm]

Qtips. or small cheap foam paintbrushes.

[MaxT]

Qtips. or small cheap foam paintbrushes.

I guess those would work for product removal.

What about polishing with a compound/polish? Something that would still make it cut. Would the foam brushes work?

Something like this: