Rebucking your rivets will last for a while, but the rivet is already weakened and if you're going to rebuck you might as well go ahead and replace them.
Fixing a leaky riveted boat with paint and/or goo is a poor choice and won't last very long, the you have to remove the paint or goo to fix the problem properly.
This is a good vid on replacing leaky rivets and it's just a one man job.
https://www.youtube.com/watch?v=L0MA1-5NXjs&feature=related
You can buy the rivets online here:
https://www.rivetsonline.com/blind-rivets-en/closed-end-blind-rivets.html
...and they also sell the setting tool, but if you want a cheaper tool you can buy one at Harbor Freight for $20.
Don't forget to dip the rivet in the epoxy before installing... I like the Loc-tite marine epoxy.
Hope this helps.