I am only on my fourth year of ARA Unlimited, so I am no expert. I have tried a few methods of cleaning/not cleaning between cards. For now, I have settled on cleaning between each card. I run two wet patches using a 50/50 mix of Shooters Choice and Kroil and then two dry patches. The first wet patch takes the majority of the fouling. The second wet patch usually comes out fairly clean. And then two dry patches. I shoot between 5 and 10 shots on the next card for fouling and sighters before shooting any record targets. My barrels are normally shooting to my expected POI after no more than three or four shots. My barrels are good custom barrels, Shilen, Muller and Benchmark.
After a match I use some C4 on a mop and let it sit in the chamber for 10 - 15 minutes. I then use a nylon brush and brush just the chamber/throat area. Then a wet patch or two using the Shooters Choice/Kroil and a couple dry patches.
For storage I use a trick taught to me by Larry Parsons the year he won the National A-Line (2022). I run a patch covered well with Thompson/Center Bore Butter. Bore Butter is a black powder product normally. Larry told me to use it and it would aid cleaning the next time and reduce the number of fouling shots required. I am not positive it does, but I do it anyway, just for the memory of being instructed to do it by Larry Parsons. I do not use the Bore Butter during a match; just for storage. The tube says it has rust preventing properties...
FYI, I got the 50/50 mix of Shooters Choice and Kroil from Gene Davis in Ohio. I bought my first good rifle, used, from him.