I have Singapura's but only showed the male. He was the only Singapura entry.i talked to one of the judges and he asked my what kind of shampoo I used and I told him I took my cat to a groomer. Big mistake! I should of bathed him myself and to use a mild soap like Swave or baby shampoo.
Singa's are great, over here shorthaired cats aren't generally bathed for a show. But if you are I'd be asking the breeder what products she uses, she'll know what works best.
We bathe our silver Maus to bring out their spots, and to help them achieve the coat texture we want. Smokes aren't generally bathed, just brushed and wiped down. But, I have been advised to bath on Wednesday evening to give the coat time to develop it's natural oils by a Saturday show. I use a brightening shampoo for their white background coats - you can usually talk to the vendors at the show for advice.