I spoke to a vet regarding this, and she advised against it for me. Especially trying to spray the bottom right after they come out of the litter box. She said it would make the cat fear her littler box. I'm glad that wasn't the case for you. I just let my girl do her business and prance around for a minute before i grab her and wipe her bottom with a cat wipe. She hates it, but after i wipe, she's diligent about licking her bottom clean! i give her treats after her wipe downs, and double treats when i see she's cleaning her bum after wards. now she cleans her bottom on her own, and i don't have to worry about wiping her down anymore. I've noticed that after i trimmed her bottom hair, it has helped with her wanting to clean on her own. she's a DSH, but the fur towards the rear of her body and her hind legs are much longer. any time i catch her licking her bottom, i always give her treats. lol. that method has been working for me. I was so worried when i first encountered the issue, I thought she might have had some anal gland issue...but now that she's been cleaning herself...that doesn't seem to be the case.
We only had that problem once where our young female would not clean her bum. Hubby would take a spray bottle with water and spray it, which made her want to clean it. A couple of times doing that and she took over the job with no spraying anymore. She just passed away 2 years ago at 10 years of age, all that time, taking care of herself with cleaning. Spraying their rear-end with water would be my first step. Of course that won't help if you have a chubby cat that cannot reach the area or an old one that can't reach it. We never had a 'lazy' cat that would not give itself a bath.