I'm the proud owner of an untrimmed agility cape on a main. It's been about a year now since I've had it? I usually tended to babysit the account, and it took a steady two months to achieve.
Btw, I used Perf's bot. Being the proud owner of a number of bots, I'd definitely say his are my favorite. Good luck on your goal & if you ever try for 99, it's truly an accomplishment worth boasting about.