I just found a menaing for the word aclarar, that I cannot find in dictionaries, including WordReference. The meaning is "Wash out". I found it in the instructio for a hair colour. The sentence was roughly "la mezcla se aplica sin aclarar el serum ....", in the corresponding English instruction this was formulated "the mixture is applied without washing out the serum ...". This could perhaps be added to the WordReference.