reservior

Hi guys.I bought two new chrome reservoir caps for my max and I was wondering am I going to need new gasgets to replace the old ones or if I am carefull can I use the old ones?.

I'm flushing out my cooling system. All set but need a way to thoroughly clean out the overflow reservior. Last time I tried putting in nuts and bolts and shaking them around. It got some of the subborn stuff off the walls but not nearly all of it. Any of you guys come up with the "tool" or...