Applying Rogaine straight from the canister?

Hey guys... I just started using Rogaine yesterday.

I have longer hair, so it's tough to get it to the scalp when I applied it with my fingertips.

I saw a video on youtube where a guy just sticks the canister nozzle into his hair and applies it this way... any reason this is a bad idea? I feel like it would work better for me, just curious why I don't see this suggested anywhere.

Thanks!