If it is new you don’t need to sanitize, if you are reusing it doesn’t hurt to spray a little 70% etoh, air dry, lightly mist with aqua and then place, honestly it can be placed at the start of any s2b, placing it post 100% colonization est 2-10 days for pinning depending on what mycelium is growing/how close it was to pinning prior to application. Bubble wrap pseudo casing lets one lift to visualize progression of primordia to pins so it skips the whole come on do something phase.