Originally Posted by WhyFi

Most of the weight of sealant is water - 1-2 fl oz of sealant is pretty damn light when it's all dried up. If you're riding at a decent rate, I wouldn't bother with unmounting and cleaning out at all. If you're only putting enough miles to wear out a set of tires every two or three years, I'd wonder if flat frequency is even worth the bother of going tubeless vs tubes. If flat frequency is still problematic, you probably don't need to worry too much - you'll be losing sealant a little at a time, any way, and you'll probably have tires beat up enough to warrant replacing before the tread wears out.