2. The only solution to Mindslaver is removing it from the game. Putting in the graveyard only helps your opponent, as decks that run 'Slaver run Welder.
Here are some other solutions:
1. Win the game. Combo can win before slaver activates pretty easily.
2. Null Rod/Damping Matrix. Either of these mean no more Slaving.
3. Kill the Welders too.