Here's a pic of my trainers this morn. I did a parkrun on Sat and cleaned them yesterday. They are 11 months old.
Apart from scraping and brushing off dried mud, I clean all the grooves in the soles (even after every run) with a small flat screwdriver or pointy knife.
Wash with an old toothbrush in warm water and some washingup liquid. Squeeze off any excess water and stuff with paper. If the paper is wet after a few hours replace then remove at night.
If not completely dry next day that shouldn't stop a run.