Well, another place to look for Rukia and Toshiro fanfiction could be Tumblr. A lot of fans post their works or reblog interesting fanfics there. You might need to use the search function and be a bit patient while sifting through the posts, but it can be a great source. Some Tumblr blogs are dedicated to collecting and sharing fanfictions of specific pairings, so it's worth exploring.
Goodreads also has some groups dedicated to fanfiction. You can join relevant groups and ask for Rukia and Toshiro fanfictions. Members are usually very helpful and might recommend some great reads that they have come across. Additionally, Reddit has some subreddits related to the fandom where you can find fanfic recommendations or even direct links to some great works.