So I can definitely say that the Sonic Spa Pro has definitely helped in keeping my nightguard as clean as it can be. Been using it for about 2-3 weeks now and while it has visible improvements of removing the plaque in my nightguard, I kinda feel like it would’ve made more significant improvements. I owe that more to just underestimating how disgusting my guard really was before I got the Sonic Spa. I’ve had no issues using it and the tablets are great as well. I highly recommend including the package of cleaning tablets if you order this item. Definitely a good buy. Just wish it would make more visible improvements in cleaning all the dried plaque/nasty stuff.