That is a great advice, kmarch.
I am myself one that expects fast results. Your advice applies to me too. Lately I have become quite patient,thanks to orchids
dionysus: I have no knowledge of the agar(s) used in orchid flasking. There are so many types of agars that are used specifically for certain purposes. Tobi can tell you more about the differences.
I assume orchid growers use nutrient agar that is predominantly of plant origin (algae-galactose & polysaccharides) with some nutrients added.
Gelatin is predominantly of animal origin (collagen) and contains high amount of proteins and amino acids. Commercial gelatin is made from pig skins , I think. With the basic knowledge I have about plants I doubt if gelatin will provide a good medium for flasking. That is my personal opinion based on the composition of the two. Jello is also articially sweetened with C6- and C12-sugars. So even if the chemical compostion is acceptable for seed growth the mere concentration of solubles will kill them by osmosis. At least that is what I think.
I am sure experienced growers of orchids can give you a better assessment on the use of "jello"
But if you want to try it that should be fine. But expect the worst and think about the effort you are going to put into flasking and see if it is worth it to take that chance.
I think it will be better to follow the advice of tom499 and kmarch.
Good luck.