And no, it doesn’t involve wearing an undershirt.
Apparently, you can condition the fibers of a sweater the same way you condition your own hair in the shower.
Sounds crazy, but the process actually involves rubbing conditioner all over the sweater and letting it sit for 30 minutes until everything is absorbed. A pre-soak in vinegar helps clean the wool and prep it to receive the softening agents in conditioner.
YouTuber But First Coffee shares this and other pro tips in this video of helpful wintertime hacks.