Cleaning the back side of a seam....

[GreggK]

Im taking on re-sealing my body seams on my vanagon. They are not too bad rust wise but they are cracked in many spots and water is getting into the inside of the van. Ive been noticing it when I rains. Im going to have the van painted his summer after I do the seams and some panel replacements.
I used a wire wheel on the outside of the seam and it removed the old sealer very well. On the seams I can get to on the inside of the van I can see faint rust. The most I can do is use the wheel and get the visible rust off but can quite get into anything. This is mainly on the inside of the middle side panel behind the drivers seat. I have yet to go after the other seams yet.
Any suggestions on doing a more thorough on cleaning the seams from the inside? Thanks