The trouble with storeing seeds in frezzers/ refridgerators is temp. fluctuation from either opening and closeing the door or frost free , defrost modes , these fluctions cause condinsation that will shorten the life span consderably _ rice sounds like a good idea to help eliminate this
Long term stored seeds do not go bad all at once , they slowely lose germination % rates over the years , So if your makeing seeds for storage store lots
I store my seeds in a mason jar in the basement where the temp is a steady 55-65 year round , As long as they are properly dried (not over dryed) they will be viable for many years 20+ atleast