Locking access to embedded Excel files from within Powerpoint

This is probably more than of a PowerPoint question than Excel, but since it is at least partially related to Excel, and there is no PPT forum here, I thought I'd try my question here.

I have a PowerPoint Presentation that has a number of tables and charts were copied in as embedded Excel files. A number of these have confidential information stored on some of the worksheets. I need to send this presentation to the conference organizer, and not have the contents of the embedded files accessible. Typically we just pdf the slides and send that, but in this case we have just been told that they are assembling all presentations into one master PowerPoint file, so all presentations need to be given to them as a .ppt. This is also a long presentation, and it has taken a long time to get layout of all the tables right, so going in and cutting out each table, and then pasting in a picture (and having to do the layout on the slide again) is a definite PITA and I'd like to avoid this if at all possible.

Any suggestions?

Thanks Shg, I agree that this should be done in pdf and the files can be combined, and would probably make everything easier for everyone, as I know whoever is responsible for combining presentations is going to have trouble with formatting. Unfortunately, I'm not in a position to suggest this, and I assume they must have their reasons for wanting it in PPT.

And I'm certainly not at the level where I could convert the whole thing from objects to pictures in 10 minutes. Heck, I spent 20 minutes trying with one object and couldn't get the layout exactly as it was before. A corner I was trying to line up with was always 1 pixel too high or to low when I was trying to position the picture on the page. I'd go crazy if I had to do that with each picture.

I've ended up saving the slides as jpgs and then importing each picture as a slide. It doesn't look great, but seems to be better than any other alternative I've seen.