A competent homeowner can absolutely do some grout and silicone work. Whether they should is a different question, and the answer depends on scope and finish standards.
Where DIY tends to work: replacing a short run of silicone (say, one wall-to-wall joint), touch-up regrouting in a single area, or cosmetic cleaning. These are jobs where the finish standard is forgiving and the risk of making things worse is low.
Where DIY tends to fail: full-shower regrouts (removing grout to a consistent depth without damaging tile edges is harder than it looks), silicone at frameless glass screens (a wobbly bead reads as amateur immediately), and anything where the underlying issue isn't clearly the surface joint.
The most common DIY mistake is applying new silicone over old silicone. Silicone doesn't bond to itself once cured, and the result peels within weeks. If you're doing silicone yourself, full removal is non-negotiable.
Second most common mistake is skipping preparation. A joint that isn't clean and dry won't hold new material. Rushing this step wastes the work.
If the shower is leaking, DIY is not the right first step. Diagnose first — then decide whether the repair is within DIY scope or not.
Need this repair done?
Send photos for a written quote — no obligation.