Totally agree with Lestat999
A couple of other things I would mention that will help although 2 weeks is still a short time for them to become comfortable with there new home.
The number of Clown loach can make a difference the more there are the better but of course few of us have tanks large enough for a really big group I think the consensus of opinion is at least 4 or 5 to help them with there need for there own kind it gives them confidence and it also makes for a more amusing and entertaining group dynamic as they play.
Caves and hiding places, the more you have for them to hide away, I have found makes them less likely to hide, odd as it sounds but there you go its a genuine observation
I have also read that fellow tank mates makes a difference in that if you have other species that dart around madly like Danio's this can make Clowns a little skittish and it can take a little longer for them to get used to there environment.
They do prefer a subdued lighting set up but if you have a lot of light they will get used to it, but again it will take them a bit more time to get used to it.
For the future, I have found after reading a good bit of advice to change the position of some ornaments and tank set up when doing a clean every now and again as Clown loach are very inquisitive and will spend a great deal of time checking out the changes but I would recommend you wait a few months before trying this
Finally a power head will be appreciated as they love to swim against the flow a very entertaining thing to watch as they are very powerful and adept swimmers.
As for food Lestat is write muscles and prawns are good idea they love them mine go absolutely crazy for muscles
a nice big range of foods are a must!
Hope this helps a little and I hope your Clowns soon show themselves they are fantastic fish.
Regards onebto