You probably only need 2 drops in those pieces.
Give your pieces a thorough rinse to get off any cleaning chemicals, as
@t-dub said, and then add one drop of extract. Draw through it to mix it up and see if the same thing happens. If not, add a second if you want. You'll probably get more bubbling than usual, but it shouldn't be foamy.
If you can, give your piece a good hot water rinse before every session (fill it, maybe gently shake it, and pour out, a few times), and use fresh water+extract to fill it for use, for the best results.