Can washing machines get rid of hepatitus c positive blood on clothes?

Yes: The virus is almost as wimpy as HIV and almost certainly dies on drying or on the temperates in a washing machine.

Variables LargelyYes: More effective for destroying viruses is bleach. However, just soap & h20, esp if temp higher, will destroy both viruses & living cells, if time is long enough & thoroughly exposed (mechanical agitation). For medical/surgical instruments, like electronic sterilizer in my office (shown), distilled water heated to steam at sufficient temp, ↑ ed pressure + long enough (e.g. 20 min) + indicators work.