There's no need at all to fix modern T-grain type films forever to get rid of the sensitizing dye.(posted 9004 days ago)Fix in an ammonium thiosulfate rapid fixer three to six minutes with _constant agitation_, then treat in a wash aid for two to three minutes, then wash and dry as normal.
You can either use a commercial wash aid or make your own by mixing a tablspoon (25g) of sodium sulfite in a quart of water.