Holeless leaves on my Hosta courtesy of copper tape. This hosta, name unknown, left by the previous owners, has been repotted several times, and each year I vowed that I would throw it away, as every leaf became damaged by mid season.
Last autumn I bought a roll of copper tape from Waitrose, and during December put it around the pot just below rim level. I even emptied the hosta out of its pot, to make sure there were no slug lurking in the bottom.
My friend Liz Watson has a lovely collection of hostas given to her by another 'enfuriated' gardener, and all of her pots on her shady patio, have tape around them and were much admired at the last open garden. She did mention that you have to wipe the tape from time to time, because the tape can become compromised by splash up of soil, and the little slugs and snails soon find this out.