How to wash a crocheted vintage lined purse

I was afraid to wash a vintage old crocheted purse that my mom owned. It is in very good condition, the issue with it is that I've noticed that the purse has yellowed with age and has turned brittle. I don't want to damage the purse by washing it in harsh detergents or in washing machine. I was not sure what was the best method to wash purse and find a way to soften it again. After searching online, I found some articles related to topic; there were no articles on how to wash or care for a vintage crocheted purse. I decided to soak the purse in warm water and dish detergent for three hours then I washed the purse in the delicate cycle in warm water with little liquid detergent and fabric softener. It whitened the purse but it did not soften exterior.  I have to keep searching online for tips on restoring old bag.  This bag is very 1970s cool that's why I will attempt to find method to fix bag.

Hip fashion from the 1970s.   www.savingshouse.blogspot.com