Here is my contribution to The Hive:
I thought up this idea a while back but never found the correct nozzle to fit and make the product work correctly.
While cruizing the isles of Wally World I found a specific nozzle that will fit onto a 3 liter PTFE soda bottle. The item was on "clearance" for the price of $1.69. I don't know if they are still available now but they might be found a auto parts stores, that would be my second guess. The brand I used is from Snapware Corp under Good Idea Household Products. It's a screw-type yellow nozzle, black collar, "Refill Spout" used to attach to all purpose cleaning containers. It comes with one size changing adapter and just happens to twist perfectly onto 3 liter soda bottles for all your clandestine needs. Once the funnel is assembled in under 30 seconds the bottle can be used just like any other sep funnel with a minimum 2 to 3% solvent product loss on each wash. When the items was tested on 2 occasions it was found that 70% of solvent volume was recovered after 10 washes and 80% recovered on the other test doing 7 washes.
Simply use the container as you would use a sep funnel in the exception that your twist-type nozzle will work in-situ of your stopcock. You can control your flow rate by slightly squeezing the bottle and/or opening the nozzle more. The only thing you must be careful of is the suckback of bubbles into the funnel which may cause some of the solvent to be released upon pressure equalization. Practice with it a few times before using it with your intended product. The nozzle is good for 2 or 3 uses until it starts to leak slighly or the threads become stripped. Some chlorinated solvents like DCM may tend to soften PTFE plastic so I don't know exactly how well it may or may not work with that particular solvent. Saturated Methylamine solutions in some really stinky amalgams may also cloud the PTFE bottle after storing for several hours. Do not keep aqueous methylamine in this bottle. However, most organic solvents like Toluene, Xylene & Ether will work fine. For $1.69 for the nozzle and another $1 for the 3 liter pop bottle you have a useful laboratory product for under three clams.