I agree with Mentat.

Tho.. when i first got Gigs, i had tge coco substrate and he accidentally ingested some and ut didnt turn out well... he threw up his entire supper (two crickets) and some yucky gooey dead stuff mixed with the substrate and started a shedding and couldnt finish it properly.. all that at the same time and i jyst happened to have a look at him at the same time..

I changed the substrate to carpet and i dont feed him in his main tank anymore either.. thats just me. Worried too much. Lol

To my opinion, if you have any kind of "loose" substrate, proper or not, id feed them in another tank so the risk of ingestion isnt there.

Good luck

PS.. for the weird sounds.. ill be honnest i have no clue. Never heard of a clickibg sound coming oyt of a frog other than a "bone crack" lol