There were huge aluminium tanks filled with liquid (bubble bath, shampoo etc) which were brought into the main floor at Riverside Works. These were what fed the filling machines at the far end of each belt. These odd little machines were always covered in gunge from various spillages. In the backs of them were two rods which you twisted to adjust how much liquid came through (not an exact science). You could fill two bottles at a time and any overflow dripped into cream coloured bowls (looked like washing up bowls) underneath. Once full, these would be emptied into one of the nearby sinks. (I’m not entirely sure whether we were supposed to do that!)
The trick was to wait a few seconds for the bottle on the left to be half full, and then put the bottle under the right hand nozzle. When the right hand bottle was half full the left one was full and could be placed onto the belt to be capped. This involved great co-ordination, as the smaller bottles took just a few seconds to fill! You always tried to have an empty bottle in one hand and a full one in the other.
After a day of having your hands covered with chemicals, some of the girls ended up with very itchy skin. I vaguely recall that the chaps working behind the scenes with all of the chemist stuff would provide tubs of cream to alleviate the symptoms.