Pretty much all wrasses are prone to jumping. Best bet is to jump proof your tank.
If you have a canopy, that sits atop of your tank, you can run a line of gutter guard across the back opening. If your top is wide open, there are screens that you can make to cover your tank that wont interfear with gass exchange/light penetration. You can also just sit back with your fingers crossed.
Waiting the flatworms out sounds easier than it is....The will get to huge proportions before they dwindle away, and can smother corals out in this process.
Best bet, if you arent comfortable using a chemical, is to keep siphoning what you can and let a wrasse take care of the rest. If I recall right, there is a damsel that is prone to eating flatworms also. Cant remember for sure.