Aveeno Bottle Coupler, Improved

Update 2023-09-26: There's a new version (r5) with a vent for the lower half; I think this will make the Aveeno flow better. I've also revised the outside grip and chamfered the top/bottom for easier handling.

This Aveeno bottle coupler allows you to easily attach two bottles together to drain what's left in your old bottle into a new one. There are other versions of this floating around, but my improved design incorporates a funnel for the receiving bottle to keep things extra clean.

After much testing, the proper way to use this is create a slight vacuum in the receiving bottle, then tighten up the cap and tap the donor bottle a bit. Do this a few times and you'll get nearly everything out.

I used Xavan's Necks & Caps for DIY projects library: https://www.thingiverse.com/thing:1654620.