charlest -- Here's a quote from the list of approved/non-approved cleaners and polishes section on bowl.com:
"In the past few years, many new polishes, which are designed to change the surface roughness of a bowling ball (the same as abrasives such as sandpaper, Scotch Brite pads, and Abralon pads), have been introduced in the market-place. These products, which contain solids or abrasives, are normally thick (high viscosity), paste with the consistency of car polish. Since they change the surface roughness of the bowling ball, these products may only be used before or after certified competition"
However, you are correct that Hook It (Liquid Sanpaper) is on the approved at any time list. I am not familiar with this product, so I assumed that despite the name it doesn't contain abrasives. If this is not the case USBC let this one slip through the cracks and will certainly rectify the mistake with the next list. -- JohnP