Lots of peanuts are sold in jars if you already eat them. Also any local grocery store should have cases of jars. I just paid $8 for 12 jelly/jam size jars which are a little small but work perfect for my situation.
flushing=myth! ask any prize winning tomato grower if they flush before harvest. Why would you want to remove nutrients when the plant is swelling and growing and consuming the most? It will finish when it is ready. Patience.
brimck- my last grow I flushed one plant kept feeding the other...