You’d may want to check the Wisconsin regulations on using frozen smelt for bait. I’m not familiar with Wisconsin fishing regulations but going to the grocery store to grab frozen smelt out of the frozen produce cooler may no longer be legal in Wisconsin with all the new VHS laws that have been put in place the past several years. If using frozen smelt bought from a vendor, some states require the smelt to be Certified VHS Free and/or preserved by a bait dealer using accepted methods known to make the virus inactive.