Hi Jodel and welcome to the forum!
Whether or not to deadhead Rhododendrons is a topic many experts disagree on, believe it or not! Some say it is a tedious waste of time and therefore one shouldn't bother doing it. Others, however, point out that deadheading prevents the plant from spending all it's energy on forming
seed heads rather than on next years buds.
So I guess one question you need to answer is do you want
seed heads or not? If you don't care about the
seed heads and would prefer a greater density of buds, then you can deadhead freely.
Merme