I have tried a couple of the floats sold by tackle tatic, The ‘Floating Beads’ seem to work well and are very tough. I use the Luminous spotty 10mm ones.
Also tried the Bait Rig Float Beads, they seem to work well but start to dissolve after a few uses. From memory both can keep a chunk of pilchard off the bottom… But my memory is hazy, would need to test them again.
Recently I been tying myself a few using this method
I have not fished any of mine but they float well in the sink.
The last option is to important a bunch of Surf Poppers from Ebay, I get mine from happyfishing188 and they work out to be a couple of dollars each.