This is mentioned in a section which lists "many exotic new facts" that can be acquired by spending time "around a Substance-recovery halfway facility like Enfield MA's state-funded Ennet House.
A Texas Catheter is a condom-like device that allows for external urination, as opposed to fitting a Catheter internally. Enjoy this exotic new fact.
This reference spawned a painting that featured in an art show inspired by Infinite Jest, entitled A Failed Entertainment: Selections from the Filmography of James O. Incandenza.
Artist/curator Sam Ekwurtzel gave an interview prior to the show's debut on January 29 2010, where he explained the relevance of the Sierpinski gasket:
"And then there are a couple of paintings. One is [...] a painting of the Sierpinski Triangle, which David Foster Wallace referred to. He said that the structure of the novel was based on the Sierpsinski Gasket, this sort of structural triangles-within-triangles, and if you were to sort of magnify that structure, it would infinitely reproduce itself. The novel has this sort of leaping structure of narratives within narratives, so at any point, you can pick up the novel and start at any point, and the story will sort of repeat itself if you read it as a loop."
The world of Infinite Jest is set in a future where North America has become one unified state known as the Organization of North American Nations, with corporations buying the naming rights for each calendar year, creating the concept of Subsidized Time.
(1) Year of the Whopper
(2) Year of the Tucks Medicated Pad
(3) Year of the Trial-Size Dove Bar
(4) Year of the Perdue Wonderchicken
(5) Year of the Whisper-Quiet Maytag Dishmaster
(6) Year of the Yushityu 2007 Mimetic-Resolution-Cartridge-View-Motherboard-Easy-To-Install-Upgrade For Infernatron/InterLace TP Systems For Home, Office Or Mobile
(7) Year of Dairy Products from the American Heartland
(8) Year of the Depend Adult Undergarment
(9) Year of Glad