A better way? to keep RTV usable.

Not sure if this works or not with RTV. But where I work, we use a lot of Urethane for windshields. If we have to touch up a spot the robots miss or someone puts their hand in it, we use a chaulk gun with it. When done, we use a rubber glove/fingure over the end. Squeeze the trigger to fill figure up, then twist above lump. Next use, just pull glove/figure off end and use/repeat.