Voting for third party candidates or not voting at all in a particular election is a good way to get rid of RINOs. We have GOT to let the moderates who control the party to know that there is only so much we will tolerate.
As noted before, that's a job for primary elections and grassroot organization.
I realize that the primary route doesn't always work. I also realize that the party bosses will often back a RINO.
But the solution to both those problems isn't to elect a democrat. That only buts a guy whose against you 100% of the time in power over a guy whose against you 50 to 95 % of the time (actual percentages may vary).
The solution is to take over the party apparatus.