Hi You can do mild exfoliation using loofa during bath and apply mositurizer or coconut oil over damp skin to seal the moisture.

Oil application good..few creams available.. for detailed prescription do direct online consultation with photos

Ichthyosis and dryness of skin have impaired skin barrier . If you induce more Exfoliation , this can lead to more loss of protective skin barrier . Actually Dermatologist prescribe good topical moisturising creams to maintain this barrier in such skin conditions. These creams / moisturisers also helps to retain water and keep skin moist, helps to loose dead layers of skin. Yes you can apply coconut oil after bath