I never have, and most people don't. That said, I've decided if there's a hot race in the next few weeks I will take one of the small bottles from an old running fuel belt (about 4 oz) and stick it in a jersey pocket. There's not much chance to drink in a typical cross race.
At 30min to 60min, you don't really need it unless it's really really hot. If it's hot, the race officials may allow handups. Otherwise, hydrate well the night before and day of the race. Being thirsty, along with the pain, and being wet and cold, it part of the suffering fun. Love it and embrace it.
There's not much chance to drink in a typical cross race.
Almost all start/finish areas are flattish pavement. If you're racing 40 minutes or more in early-season heat, icy water will help, at the very least psychologically. A wire bottlecage on the seattube won't get in the way for most people. Or jersey pocket, tho' that heats the water pretty quickly. Best option is a handup, check with the race organizer for the rules.