Most direct vents use a fiber ceramic. I don't know how it would stand up to a hose and a scrubber brush. What model of fireplace do you have? Do you possibly have cement logs? I am surprised all the paint did not come off. Either way I don't think that was a very smart thing to do.
If they are fairly heavy they are cement, the fiber ceramic logs are light and you can easily damage them. I think the 6000GDV had a large log in the back, and a smaller one in the front, then two Y logs that spanned those. They are cement if I remember correctly. If you let them dry out thoroughly I don't think any harm will come.
Try putting them in your cooking stove for a while at low temp (maybe 150 degrees or so). That ought to dry them out good. The problem in the fireplace is that they get heated unevenly and the water trapped in them could cause problems, heating them gently should get the water out.