Giving enough think time.... using signals

In my small group, we read a decodable together after we review the phonics concept and blend the words. It is hard to give students enough think time during a read through together. I use a dog training clicker to time the think time. I tell the students to think... and when they hear the click they all read together. This way your strong reader in the group doesn't dominate and everyone gets a chance to blend it in their head before reading.
I feel weird using the dog clicker but it is the best thing I have found and it is really cheap at Petco.

Do you use something as a signal? I would love to hear other ideas.