Good but not great
Overall, does the job. Works on the 1.5 L bottle of Listerine and fits perfectly, straw leaves about 2-3mm of room from the bottom of the bottle. My only gripe is that it takes a few pushes before any liquid ejects with each use. It also takes several pushes to obtain enough fluid for the recommended quantity to rinse. All in all, I still prefer it to squeezing/turning open the cap and inverting the bottle with each use.
Rating: 4 stars