Don't have my Axo set up at the moment so can't check, but if I recall, the Sample-Scrubber example that lokki made for me demonstrated a loop also. Don't quote me on that, I know something I asked for did and I think that might be the one, but if not, at least it will teach you how to do sample-scrubbing really easily!
Just look for the SampleScrub2.axp added by lokki in this thread:
Regards working with longer samples from the card, I hear it can be done somehow but I asked about this not so long ago and no one seems interested in this at the moment. I think the problem is the current situation is not ideal and I get the feeling the members here who code objects are steering clear of coding such objects until some technical changes are made to the way things are done.
I've wanted to make a digital SD-Card based recorder for example, and can't because there are no full-duplex objects around yet. I believe things need to be super-optimised in order to do this stuff on Axoloti and have asked for super-optimised full-duplex objects. The good news is I did get a response from King Axoloti once, but none of us know if or when this stuff will arrive. I've always been surprised that out of all the coders and contributors on here, none have designed dedicated super-optimised full-duplex objects, but they haven't, so I've just had to accept it ain't gonna happen until changes are put in place to how things work.
Anyway, here's the thread if you're curious: