rust converter

i have a 1999 tj that is in great shape. I was checking out the inside of the frame and there is a lot of flaking and junk. I don't want to cut holes in the frame. I tried to blow some out with my air compressor. I read many posts on this subject, but it looks like everyone cuts holes. How...

So my friend moved to Texas and he sold all his stuff, and I ended up with a jeep. I've never owned or tried to own a jeep but it just fell on my lap. So I'm new to all of this. It's a 02 TJ, 2.5 5speed. I'm from Nova Scotia and the winters here can be vicious on vehicles. I've been underneath...