Is it permissible to use anasheed with sound effects other than the daff (tambourine) at weddings to avoid playing indecent songs?

Sound effects are of two types: the first consists of natural sounds like moans and chants without modification, and this is permissible. The second type involves effects processed programmatically to resemble musical instruments, and this is not permissible; its ruling is the same as that of forbidden musical instruments, and it is not allowed to use them.

As for the rule of repelling greater harm with lesser harm (committing the lesser of two evils), it is correct and applies if one of two evils must be committed, in which case the one with lesser harm is chosen. Playing anasheeds with forbidden effects is not necessary to get rid of decadent songs, as there are permissible alternatives. All forbidden things must be abandoned unless one of two forbidden things must be committed, in which case the one with lesser evil is done.