You don't need to hand pollinate basil to get viable seed. I don't hand pollinate tomatoes either, so I'm not sure what what you are referencing. I don't think cutting basil is great as a permanent solution as this is an annual plant that is useless after making seeds.

Hand pollinating indoor tomato plants just means to lightly shake or tap the stem with the flower. Some people use electric toothbrushes to encourage pollination. Tomatoes are self-pollinating, but they still need some help without bees or other insects when grown indoors. That's what I've read and what I did before they were placed outside.

As for cuttings, I would do that before the basil flowered if I were not able to get the basil to seed successfully. I know some people do that to keep a continuous supply of basil before the basil flowers and to prevent the basil from turning bitter. In my case, I have no plans to keep the basil outside and I would like to try to collect some seeds to plant at later date.

Do you keep your basil indoors? If you do, does your basil still provides viable seed without any intervention? Or do you keep your basil outdoors. I just want to confirm. Thanks.