There is this local saying that if you sell a particular food, there will come a time that it wouldn't freak you again but then again, this is money we are taking about. I think a casino knows and understand how risky gambling can be for people, they wouldn't allow their staffs to gamble while on work, their major duties are to attend to customers and make sure that everything goes well for them and if anyone found breaking the rule will be sack or suspended.
If I am employed to work in a casinos, I will make sure I don't used my money to bet, such thing go well and at the same time back fire. However, if get tipped sometimes by customers, I might want to do put some on games and see that is if the casino company is allow the staff to bet and they pay minimum wage for their staff. I learnt that some places doesn't pay upto minimum wage that's why tips are allow, so I will do that in rare occasions.
What do you mean by it wouldn't freaked us again? But from the word freak, it is we will get surprised or get shocked, up to the point that we will avoid it, which I find very weird as a connection to the first sentence that you gave out. Basically if we are selling a food, we will also taste test it and then we will also ate that food. It is inevitable. The same goes for other types of business or work, I mean as long as we are exposed to them, we will definitely consume them.
Maybe there are only some exceptions if we are talking about hazardous stuffs because they are of course deadly once ingested in our body. Not just on a casino but on any working environment, we are also not allowed to play during our working hours, unless only if our managers or bosses say so. Even if we are not working in a casino, we are still trying our best to not use our hard-earned money on the casino games because we already know how devastating they are even if our only intention for a while is to unwind. If we got a tip from our customers, it shouldn't changed our decisions. We must only be thankful, happy & contented, and just use the money on more important things instead.