f you do not have any mold problems to deal with then you need 3 - 5 gallon buckets. Bucket 1 has tepid water with 1cup of lemon juice and 1 cup of Baking soda. Bucket 2 is tepid water. Bucket 3 is cold water. Dip your branches in the first bucket an swish around gently, rinse in the second bucket then a final rinse in the third. Shake gently to remove most of the water and hang to dry like normal. Change bucket 2 often.
If you have mold to deal with then add a bucket in front of the others with cool water and a cup of Hydrogen Peroxide. Let the buds soak a few minutes in this to kill any mold spores then use the other 3 buckets like above.
Don't worry as none of this will be detrimental to the quality of your end product. In fact it will enhance it. I cannot grow outdoors here so have not had to wash too many crops. I did get a white Fly outbreak once and them damn little bugs were stuck dead to the buds. They just washed right off and the bud was excellent.