Thx for the suggestion, but ultrasonic cleaner here are pretty hard to come by and all cleaner selling for sub US$50 (i.e: knockoff of already cheap Chinese brand/brandless) has piss poor review. Plus I never have problem cleaning everything else with warm water, just think an F deserve more than warm water cleaning and a investing in a decent ultrasonic cleaner for one -off use/that I will only use rarely doesn't seems worth the money TBH