I presume that the end-product is ready-to-eat.
Yr description of the use of rags sounds, to me, hygienically questionable in many ways. I would personally recommend you to avoid use of rags altogether for the food / food contact surfaces. If somehow unavoidable, i suggest to at least validate their BPC acceptability, do not re-use, and dispose at appropriate intervals.
I have no direct experience of date processing and it is not quite clear as to the technological level of yr operation. I deduce there is a majority of manual handling. This would normally require substantial hygienic control, eg environment, equipment, personnel, for a safe RTE end-product.
As far as initial use of rags for product cleaning is concerned, I note from da3 (below) that this is not unusual for date cleaning purposes. If unavoidable, the sequence in da1 seems a little superior (to me) to the one you describe although maybe still having significant hygienic risks, even with subsequent antimicrobial treatment.
As far as more advanced processing / use of antimicrobial chemicals is concerned some typical options are in the sections on “dates” / “sanitizers” in the articles below. A typical example (da8) is –
Wash and Hydrocooling Water
All water which comes in contact with produce for washing or hydrocooling must be safe to drink. Water should contain between 100 and 150 parts per million total chlorine and have a pH of between 6 and 7.5. Chlorine use prevents the potential for cross contamination of all produce in the washing or hydrocooling system, it will not sterilize the produce. Change the water in dump tanks and hydro-coolers regularly.
Some other refs use much lower levels of free chlorine, eg 1ppm, others use different chemical systems. I suggest that specific advice is obtained for yr product.
da1 - Date Harvest & Tutorial (Pictorial).pdf 9.48MB
da2 - date production.pdf 1.05MB
da3 - postharvest handling.pdf 4.89MB
da4 - postharvest sanitation,sec.9 - 2013.pdf 184.83KB
da5 - cleaning and sanitising fresh produce.pdf 518.97KB
da6 - minimising microbial contamination on fresh produce, 2006.pdf 117.16KB
da7 - FAO, processing tropical fruits vegetables.pdf 966.7KB
da8 - chapter 11, FAO, Small-Scale Postharvest Handling Practices.pdf 67.77KB
Rgds / Charles.C