I purchase 1,000 crickets monthly-purchase 7/8" ones--not full grown. DO NOT purchase from a cricket bait shop. Those are fully mature crickets and have a very short life span. I order mine from www.reptilefood.com
I actually save about half the cost by ordering online even with postage.
(1) Get two (2) ten gallon aquariums. Line them with either STERILE peat that has NOTHING in it whatsoever (NO perlite, and certainly no chemicals-just sterile peat) or coconut fiber such as bed-a-beast. About an inch. WIth good pet covers. Put approximately half in one fish tank, and the other half in the other.
Have good climbing materials such as pieces of egg crate, and a few empty cardboard toilet rolls--but LEAN them-not straight up and down. Crickets are stupid and can literally starve themselves to death by hiding in those toilet rolls. If you use them (not necessary but the make gathering them easy)-shake them out once a day prior to daily routine care.
(2) Remember you must take care of them just as you do with your pets. Daily mist the sides of the aquariums with water. Find a very very shallow water dish-shallower and smaller the better. Those used for hermit crabs are okay. In case the cricket falls in it is very easy to crawl out. Daily change this water.
Yes I tried the potato method-although okay, nothing beats a once a day misting and very shallow dish. For longetivity of the crickets you ABSOLUTELY MUST mist the sides of the glass once a day-everyday. Crickets love it!
(3) Food: I like either dried high protein kitten food, or a high quality hampster/gerbil pellets. Put them in a SMALL dish-in fact have about two small dishes in them. The idea is to keep the bed-a-beast/peat from getting on the food and spoiling.
Believe it or not-that's all they need for gutloading.
(4) At least once a day, with forceps, remove any dead crickets. Using the above method the fatality rate is very low. Every few days change the food. Now if you see any kind of mould growth by all means remove that food and clean the dishes and put fresh food in.
I would toss the oatmeal-it molds too easily, and if you let mold stay in there kiss your crickets goodbye.
JadeFox