Must one repeat the prayer if one performed ablution while one's hands were sticky due to laundry detergent, and does this scrupulosity affect the validity of the ablution and the prayer?

For ablution to be valid, water must reach the skin. Therefore, the presence of a tangible barrier that prevents water from reaching the skin invalidates the ablution. However, the sensation of something that is not a tangible barrier — such as the trace of henna or liquid oil that does not prevent water from reaching and flowing over the limb — does not affect the validity of the ablution.