Harris is getting that from Suetonius, who claims that there was a rumor that Caesar plucked out all his body hair. It's mentioned in a list of Caesar's rumored eccentricities in dress and appearance, not long before Caesar's effeminate tunic is pointed out. No other source mentions it, and while it's certainly believable (removal of body hair by plucking, singeing, or just shaving wad not at all uncommon even among men) its inclusion is clearly to add to the vain, eccentric, and often (as in this case) effeminate nature of Caesar's appearance that Suetonius is trying to convey--this is standard Suetonius rhetoric, and while it may be true it's really up to you to decide that, there's no other evidence besides taking Suetonius' word for it