bahaha having a background in both culinary and chemistry, aswell as a hobby of pharmacology, i can say two things. the OP's little plan is 100% fabrication. the reason it may have any effect is the step telling you to piss right before you piss for the test. only good advice in it.
and two, the guy above me is a complete douche.
1) gelatin does not congeal unless it is bloomed in hot water first.(hotter than 98.8*)
2) even if it could, or you boiled it first, it needs to sit in a sub 60* environment for several hours for the gelatin protein to stiffen.
3) your stomach will never hold 48oz of fluid long enough for it to set.
4) water is not absorbed thru the stomach lining
5) metabolites are filtered out by the liver and kidneys then excreted directly into the waste.
6) broken down cannabinoid metabolites are formed, transfered, stored in, and removed from lipids processed out of fat globules .
7) excess water in the body is handled by its own system. this system does not interact with the lipid system.
8) gelatin is a protein which is dissolved from ground animal bones using moderate heat, and a big vat of hydrochloric acid. your stomach is a 99* bag of HCL...
word. logic and 10min on google does wonders.