They're .22LRs and shouldn't take much cleaning, unless bores were put away clean, but unprotected. I've never seen a .22 LR barrel that hadn't been cleaned, actually rusted, despite having the outside surfaces rusted and pitted.
I'd just run a few patches with solvent, then use a bronze brush if they were still not spotless. When done cleaning, put Break-Free on a patch and run it through.
You probably don't need to clean the bores very often, unless someone shot lots of .22 Shorts through them and eroded the chambers. In fact, you can do more damage cleaning a .22LR bore than shooting it.
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