Yeah, one dice 6 times. Some people roll 6 dice one time to speed things up (just be sure to have consistent, unbiased way to order the dice (ie. left to right)
The instructions are very clear - if you land on a blank square, re-roll all 6 dice. Re-rolling the last 1 or 2 would reduce the entropy a bit (I don't know exactly by how much).
Saying too much does reduce the search space that an attacker has to target. But security through obscurity should not be relied upon. Especially in the age of AI.