what barbarian said, and that's all i have ever done.....the 'shake test'......but i don't do a 'careful shake test', i give the frame a good hard shake, if anything flys out, it doesn't get extracted, but these are usually on frames less than 90-95% capped. like others beeboy, with what you have capped, i wouldn't worry about it and would feel confident in extracting the honey. have fun, enjoy, and make your customers happy as well!