Silicone spray may work...
Meh...
When I service the switches I remove and open them, then remove the kinematic inside (preferable while holding the assy inside a freezer bag, so tiny, spring loaded items won't vanish into other dimensions...)...
Where plastic moves on plastic I apply a dab of silicone grease...
Where metal parts are moving a dab of waterproof marine grease...
And the contact surfaces get a drop of ACF-50... (Q-tips and tooth-pics are valuable tools...)
This form of maintenance lasts for at least two years...
BTW: performed the same procedures when we'd obtained the NT700VA for my GF... as well as all electrical connections I could thing of at the time, including the switch-plate on the ignition lock (same measures as above...)
The observant gal she is, she noted that the LH t/signal starts with some delay... the RH again flashes instantly when hitting the button...
In lack of ideas I unplugged the t/signal relay (probably the only connection I'd overlooked during the "big service"), gave the 3 pins a whiff of ACF-50 and plugged it back in; and what you know: since then both sides firing instantly...