Well! how about you? Have you ever managed to withdraw winnings without making a deposit? Is yes! Did you use any special technique besides luck? (Feel free to share the amount you won if you’re comfortable.) Your experience could be helpful to others.
Most casinos do not offer registration bonuses if you have not yet funded your account, as it is believed that funding your account is the final step in a successful registration. Some casinos give 70%, while others give 100% of the initial funding. For example, if you deposit $1000, you will receive $1700 or $2000, depending on the percentage of the bonus.
As the OP mentioned, this bonus offer has conditions that must be met, and the conditions favour the bookies. Even if you try to withdraw the funds and use the bonus, you will automatically lose it. Personally, I have not been able to withdraw winnings from a casino using a welcome bonus.