I saw a thread where somebody used a canteen strap for their Pulse Rifle sling. Any advice? I know most people use a Noble sling but I just like to see what all is out there.

Yeah, those are the best two options. Noble's custom made sling is by far the most accurate option and even uses real-part clips.

The common "canteen strap" (or some call them Army utility straps) work nicely in a pinch. They are durable, have the color, and length to look the part and get you by. However the straps come in 3 different materials and some look better than others. There are canvas (old style) a shiny nylon, and a nylon with a heavier weave that isn't as shiny. Personally I prefer the thinner nylon ones because they have that 'sheen' to them like the real Pulse slings. Overall for ~$6 it is hard to beat either way.

Just don't confuse the two! Every now and then some one on ebay tries to sell common $6 straps claiming them to be "pulse rifle" slings and wants $50 each. It is a scam. You can always tell from the ends/clips.