I would not recommend it. Have you tried a medical supply store? You can also buy one online from a medical supply website or even from a number of kinky web sites. Personally, I'd go with the medical ones as they are often cheaper.
Try Arista Medical supply in NY. A fansler is probly the biggest anal spec. But it is very expensive. Even the Hirschman go for $200. But they are 5 1/2 inches long and 7/8 of an inch wide. As for vaginal spec. Get a Graves, they are the bigggest. The large size is 1 1/2" x4" Open wide.