The last time entrepreneur Myra Vargas was pregnant, she had to keep away from her family's dry cleaning business to avoid a chemical that probably causes cancer. And when her children were young, they couldn't spend time at the family place of business. But Vargas is hoping that won't be the case if her niece and coworker, Diana Vargas, decides to have another baby. J&P Cleaners is hoping to become one of the first cleaners in Massachusetts to stop using tetrachloroethylene, better known as perc, and instead use a method called "wet cleaning." "We can be the first.