Is it obligatory to remove the water-insulating silicone material from the hair before washing, and what is the ruling on prayer with it present, and is it obligatory to search for water-insulating materials in shampoos before using them?

It is permissible to use silicone for hair if it is not harmful. Its removal is not required for Wudu' (ablution), but only for Ghusl (ritual bath) from menstruation or Janabah (state of ritual impurity); because Wudu' is based on lightening the burden, and its requirement is only wiping. The Prophet, peace and blessings be upon him, wiped over his matted hair. As for Ghusl, it requires water to reach all the hair and the scalp.

Sheikh Ibn 'Uthaymeen said: "It does not prevent a pilgrim from having matted hair with glue or the like. There is no harm in wiping over henna during Wudu' even if it prevents water from reaching [the hair], but it must be removed for Ghusl from Janabah and menstruation."