Isn't it strange how lens pens are kinda underrated? I read a piece on a photography site that called them the best kept secret for field cleaning. Mine lives in my camera bag and has saved me so many times. The only downside is remembering to clean the brush end regularly so you don't just push dust around.
When I was shooting in the desert last year, I noticed fine sand gets stuck in the brush hairs differently than city dust. It made me realize the brush material might matter more than we think, like if it's too stiff it can scratch, too soft and it just moves stuff around. Actually, I read that some pros use a separate microfiber cloth to clean the brush itself after every few uses. Kinda makes the whole 'pen' part less handy if you're adding steps, but still better than a dirty lens.