What are you trying to repel? Soap Suds work for Greenfly!
Rosemarie.....We use Spectracide from Lowes...it is not a DIY but works great!
Here's an article on Japanese Beetles which commonly affect roses: https://thekitchengarten.com/how-to-get-rid-of-japanese-beetles/
I just use soapy water on my roses.
I follow a botanist locally. He says one tablespoon of Dr Bronners castile soap in a spray bottle is best.