The method I used was like spitting on your finger and cleaning a bead of caulk. Apply it to the whole area and wipe away with a wet cloth. Honestly it took less than 20 min doing it this way. I couldn't imagine putting it in every groove. I used my finger by the end to just smear it all around, and it stays even in the small grooves of this host when wiping away. Very easy. With the lights on it a very faint translucent line in the grooves. Hardly noticeable at all. And the shadows of the grooves make it look like it's not even there. You would never notice it unless you were told or actually turned the lights out. The glow time on this color is good too. I left it to dry for a while came back to it still glowing. Having this many lines makes charging the glow areas evenly a challenge, but the pen you gave me working great