Glasticon and Glasticord are Bostik / EvoStick products intended for body-sealing against water ingress.
I would imagine that a general purpose mastic or silicon sealant would suffice as a replacement.
http://www.plumbingplace.co.uk/Evo-S...FWOWtAodJxIAZA
http://www.bostik.co.uk/diy/product/...ame-Sealant/55
http://www.bostik.co.uk/diy/product/...one-Sealant/54