I used an approach to boilerplate dummy text like this. Once. It's all it took, because I immediately got a report in our issue tracker that FireFox renders the text with boxes.
Now we routinely copy/paste similar content from similar pages and use that in live mockups.
The correct thing to do is determine how much of the complaints you get have to do with lorem ipsum, or if a little bit of additional explanation might be useful for your new/prospective clients when they see the site for the first time.
Everyone will hear complaints from their customers (I hope, or they wont have customers for very long), the question is if that is a problem that fixing will save you time or make you more money.
My read is not much of either.
If you want a fallback like this black box font for the clients who wont/cant be educated that is fine, but you might want to consider firing your client if they are causing enough exasperation that you create entirely new fonts.
