Don’t use dishwashing soap. It contains degreasing agents which remove the substances which make the rubber pliable. As Millercarbon said, if a cleaner is required, use car wash soap, only very diluted, and be sure to rinse all residue off after cleaning. I would avoid car wash soap that contains finish protectants (claim to be be “wash and wax”). Meguiars Hi Tech wash or other paint shop friendly products contain no silicones that can leave undesirable residues behind.
