And what kind of weird rules do you play also Dorothy?! I refer the honourable lady to the Wikipedia article on the history and rules for Dominoes from which I quote:

Most domino games are block games or draw games. In draw games, players draw from the boneyard when they have no matching bone. In block games, players pass and forfeit the turn when they have no matching bone.

So, if they don’t have a matching tile (or bone) then they either forfeit their go OR they pick a new tile from the deck (or pack). These are the standard rules for dominoes. You can see these also at Masters Games, which says

If a player can lay a domino, then it must be played. Otherwise the player “knocks”, or raps the table and play passes to the next player. The opposing players will, of course, make mental note of the numbers currently available on the table and try to ensure that they are available in future too…

I have no doubt that there are many localized house rules in play that allow zero tiles to be used as wildcards, but this rule is not included in any of the standard Western rules for dominoes.

The Domino Games website is another good source of information about games that can be played with domino tiles. I’ve just had a cursory read through the various rules and I can’t find anywhere that says that blank (or zero) tiles can be used as wildcards.

This is dominoes not Scrabble. In Scrabble the blanks represent any letter. If you can’t play a tile then you can’t play on that round — you don’t just lay down anything.