I don't have a Mini.....yet, but I used to be quite festidious cleaning my WSM and other grills.
Now all I do is, give the grates a quick brush when it's still warm. Dump the ashes when it's cooled, then brush out the bowl with an old 4" paint brush. For any burnt on residue in the charcoal bowl I use a plastic car windscreen scraper and give it a quick scrape. Just before the next cook I'll give the grates another quick brush.
If I haven't used a grill in quite a while, I'll dump in a full chimney of lit, pop the lid on, open all vents and let it rip to burn any nasties that may be lurking.