I tried that route as well. Bought a cheapo tether switch that I ended up replacing with the OFT Roll Over Valve that has a tether built in. My opinion is save your $20 and put it toward an OFT Roll Over Valve.
Yamaha now offers a rollover tether kit, its in the accessories catalog, I put one on my nitro, it works great and was easy to install...plug and play !!!