soaking, with agitation, in a formic acid solution (100 kg salt [NaCl] and 12 kg formic acid per 1,000 litres water) maintained at below pH 3.0 for at least 48 hours; wetting and dressing agents may be added;
in the case of raw hides, salting for at least 28 days with sea salt containing 2% washing soda (sodium carbonate – Na2CO3).