Indoor rock crawling course??

[MAXXXMASHER]

Anyone on here ave any experience building an indoor crawling course? I don't mean dragging some stones inside; more like the pics from RCX in the magazines. I think I have the basic idea; I'm just looking for some tips. This is going to be geared towards the new Losi 1/18th crawler and 2.2's. I'm thinking the thing to use is the expanding foam stuff over chicken wire, then shaped and sprayed with truck bed liner to give it some grit. Is this the way to go about it? If any of you have some pics or links to sites featuring this, that would be great!