I think there is an element of confusion between revision and homework. I fully concede that revision may be set as a homework, but really, it doesn't need to be explicitly stated. I'd happily help my DC revise for their exams, if I could, although sometimes it can cause more harm than good in a misguided 'trying to help' way. I'd bribe encourage them to attend any revision sessions offered by the school, make sure they'd had breakfast before their exams, those sorts of things.
I'm not a 'showing a total lack of interest' parent at all. But I had a father who used to punch the table and roar at me for not grasping a concept when I was four. My primary school teacher indicated my maths wasn't very good (it wasn't) and my life then had a private tutor in it and extra work on maths and my mum endlessly pestering the school for more work for me, more, more, more. She must have been a complete pain in the arse. In y7, I copied the maths paper of the girl sitting next to me and got in the top set. I carried on copying everybody throughout y7 and then someone twigged and moved me down a set. They rang my mum to tell me and honestly I am not joking my mum made a bigger drama about it than when I found out she had terminal cancer three years later. She made me sit down on the sofa and took my hands in hers and started SOBBING but not actually crying and then whispered 'you've been moved down a set in maths!' She smacked me and said she was ashamed of me and tried to get my dad to smack me but he refused. My brother also tried to hang himself by the fish pond when he was in year 8 as he got moved down TWO sets. The horror.
Of course, it was all totally counterproductive as I just learned to be sneaky and copy other girls' work, in maths and science, which were my weak points, when I was younger, so it looked like i was working very hard. Then as I got older and stroppier I just gave up. I used to spend maths lessons writing out song lyrics
as I'd been moved back into the top set due to my mother making an almighty fuss just before I went into year 10 and I think once the GCSEs started it was easier to keep me there. The weird thing was I actually did well in my GCSEs, I needed quite a bit of help with maths because I missed so many basic concepts and I am still useless at retaining information and there's a lot of basic stuff I can't do. But I passed, and I got quite a few A*s.
I think I'll take some ideas from the thread, but I'm definitely not going to sit with my children, unless they ask me to, but I will ask if there's anything they aren't sure of I might be able to help with or ask their dad if it's maths as chances are I won't be able to remember!