Guest users can access Otzar Hachochma via their website,
www.otzar.org. However, they are limited to the first 30 pages of each sefer. But the maaleh is that you could use their amazing search function, although only the line with the result will show, the rest of the page being blurred. But it doesn't have the 30-page limit, and at least you'll know which sefer to look into and which page the result is on...