Or alternatively......
Take a 2x PRO storage bottles.
Cut the threaded neck + 15mm of the body from the first.
Cut the base from the second bottle.
Where they meet, abrade the outer on the larger part, and the inner on the short section.
Give each abraded area a generous coat of polyolefin primer (necessary on account of HDPE being very reluctant to hold an adhesive)
Fit the two parts together.
Apply very thin cyanoacrylate to the join, this'll find its way, capillary fashion, round the circumference of the bottle, and bond the two together.
Gives you a double entry
bottle, with a slightly larger capacity than a standard one. Capable of holding all that is pictured below. Accessible from either end - which means you don't have tip everything out just to find one thing which is inevitably at the bottom.
With this arrangement There Is No Bottom.
Bingo!