How to purify a (may be a sports) boater? i have a panama i think i can bathe it by hand...

i have a panama i think i can bathe it by hand beside the help of a detergent.freshly as we wash other clothes.Am i right? please tender your sugessions & opinons too... what should i do to keep its shape as it is? Thank you.
Where is the smell coming from?
Answers:    I hold always wash baseball type caps within the sink with for a time detergent and cold water. It will fade a bit but if will come out clean and surrounded by shape.
What a cheap forceful path to obtain dog...
Keep it's shape with a metal hanger and clean up it in the dishwasher...