I think the faucets will pretty soon be a thing of the past. Basically the faucet was invented to try out Bitcoin without having to go thru the hassle of buying it or mining it. And the purpose of the faucet with a gambling site was to try out the site or the type of game before actually going thru the hassle of doing a deposit. Because if someone didn't like dice, or the speed of the site, or the features of the site it would be annoying having to make a deposit, pay a miner fee, and then the site would have to pay another fee for the withdraw. Hence why the faucet was invented.
However as 2017 rolled around, there was massive amounts of abuse with the faucets. Basically I think it was like 0.1% or so that abused it but they took 99% of all the faucet payouts and the site had no other choice but to disable it. Because those faucet abusers almost never made a deposit and contributed nothing to the gambling website.
Hence why you will see more and more sites use tokens or some type of demo play to test out the site. Since it was becoming very troublesome and took too much man hours to sort thru all those withdraw requests which were purely out of faucet earnings.
It is easy to counter faucet abusers.
Put a 5 min cooldown and reduce the amount to 1 satoshi. If this is not going to suffice, just cancel any withdrawal requests if the player didn't deposit any coins from his own pocket. (this is a bit extreme but its a valid option)
The faucet ,as you said, is there for you to try the casino, nothing else.
If i recall correctly both Primedice and Stake won't allow faucet farmers withdrawing without making a first deposit into their account for safety reasons and abuse prevention as stated.
I just do not know if that is still a thing currently.