Inspect the sides of toilet paper rolls in public restrooms for small red spots (purportedly from cleaning needles) or, for extra safety, bring your own fragrance-free, biodegradable wipes.

noli's read

While this warning is well-intentioned regarding hygiene, the idea that toilet paper rolls are commonly used to clean needles is considered an urban legend by harm reduction organizations, such as the National Harm Reduction Coalition (expert opinion). In fact, paper fibers would likely clog needles, making this practice highly improbable. Furthermore, according to WHO pathogen transmission data (expert opinion), viruses sensitive to open air degrade extremely rapidly on dry, porous surfaces like paper, making the risk of transfer almost zero. The concern generated here is therefore scientifically disproportionate to the real risk. Nevertheless, using one's own wipes remains an excellent habit for comfort and overall cleanliness in shared spaces.

the sources

No named source held this one up — that absence is part of the verdict.