Crossbreeding Echium pininana with Echium russicum?

I have some Echiums, and i was wondering if i could crossbreed my pininana with my russicum.

My idea was to just cut some stamen from my russicum and rub those against the stigmas of my pininana with some tweezers or something, and cover the flowers with something like rolling paper.

I could pollinate three specific flower branches for the rest of the season, and keep those seeds apart from the others.

Luckily the flowers of my pininana are not as attractive as my russicum yet, so there aren't as many bees that will screw around with these first flowers.

I am completely new to hybridization, so any advice is welcome.